1. Field of Invention
The present invention relates to a timepiece wheel train for driving the hands of a timepiece, and to a timepiece having this timepiece wheel train.
2. Description of Related Art
Wear between shaft parts and bearing units normally occurs in a timepiece wheel train that drives the hands of a timepiece due to the high side pressure applied to the shaft parts of each wheel, and this wear can lead to a variety of problems, including increased drive resistance caused by wear particles produced by this wear and deterioration of the lubricating oil, a shorter timepiece service life, and a loss of precision in the timepiece movement. Addressing this issue, Japanese Unexamined Patent Appl. Pub. JP-A-H11-133162 teaches a configuration that lowers wear between sliding parts.
The analog timepiece taught in JP-A-H11-133162 has a diamond-like carbon (DLC) film rendered on the rotating shaft support member in a configuration that supports the metal rotating shaft of a rotor by means of a rotating shaft support member, and thus uses a configuration that reduces wear between the rotating shaft and the rotating shaft support member without using lubricating oil.
While JP-A-H11-133162 teaches a configuration that uses only a DLC film to enable sliding with low resistance without using lubricating oil, this configuration cannot efficiently lower resistance in the timepiece wheel train of a mechanical timepiece because of the high side pressure, and resistance increases due to wear particles from the shaft members.